What are some of the applications you have used carbon steels or alloy steels for?

139 answers

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We have used alloy steels for fasteners, fuse pins, and major aircraft structural components. However, we are not designing anything new with alloy steel due to the corrosion issues this alloy family faces in service.

Welded add on mechanisms onto a homemade pipe delivery trailer. Constructed physical racks assisting in bundling of 25' metal rods. Designed and constructed off loading racks for delivery trailer. Maintained same trailer, repairing or replacing hold down pins as needed.

~Rodney L, Marketing/Sales, Boerne, TX

Our markets are primarily in the coal fire power and mining industries; waste to energy, paper processing, aggregates, and even automotive where wear resistance is needed. We engineer all types of solutions for problematic applications.

Please share with us any “non-standard” applications that carbon steels or alloy steels have been used for.

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For an assembly press, I used H-13 due to high stresses, thin cross sections, repeated impact loads etc. It worked well, 4140 could have been used for a much lower cost unless heat treating had warped the 4140 enough to require that the part be ground. H-13 is very stable, but very expensive.

~Steve K, Project Manager, Portland, OR

I've seen some structural steel applications being used in the residential area of construction. This has been around for larger houses in the past, however I'm seeing it even in some smaller houses, ie in the 2500 to 4000 sq ft range.

Do you know of any disastrous mistakes that occurred due to the incorrect usage of carbon steels or alloy steels?

30 answers

Answers:

1. Stated material properties are based on a coupon test(s) at specified locations within the form roll. These properties may not be consistent throughout the cross section, therefore machining or reshaping steel can leave you with mechanical properties lower than the design intent.
2. Although most carbon steel and many alloy steels are weldable, it pays to check with experts if the application warrants.

~Mike R, Engineer, Edmonton, Canada

We purchased 8620 material and made some pins for a customer. This material was 8620, the certs fell within parameters of 8620, but when the material was heat treated it would not hit the hardness and case depths required. Upon examination, it was discovered that we needed to control the actual range of alloying elements within the steel to enable us to reach the correct end results.

~James D, Marketing/Sales, Kaukauna, WI

Improper baking of hydrogen caused premature failure of a spring beam. Etched-out slag inclusions led to fatigue failure of a fuse pin. Improperly applied corrosion resistant coating did not protect the alloy from oxidation.

~Dan Wallem, Metallurgical Engineer, Renton, U.S.

I have not witnessed any yet, but have heard of hundreds. They are out there, if you doubt it, check with your local, trusted material testing facility. They will be able to give you the best examples. Northwest Laboratories in Seattle is good one.

~Paul V, Quality Control, Everett, WA

When a customer insisted on taking over galvanizing of a hardened 4140 steel hook, they did not shot blast before galvanizing. The part sat in the acid for too long and developed hydrogen embrittlement, resulting in failure.

~Ralph Russell, Manufacturer, Chicago, IL

Calling up a roll pin and not realising its specification allowed for both Carbon and Stainless steels - use of Carbon steel and subsequent corrosion issues resulted in recalled aerospace product from military service.

~Neil I, Quality Control, Brighton, UK

For us, material wear life cycle is important. Choosing a material that may be subject to impact and wear limits your choices. However, we have found that combination usage in design is quite relevant.

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